Enhancements: Add Predefined models in ai-chat Instead of Input Box

[hemantch01]

1. To use the AI chatbot, users must first manually provide an API key for the selected provider.
2. while users can easily select the AI provider (like OpenAi ) they must manually type the model name.
3. Since the model name is entered manually, there is a risk of incorrect input due to typos, extra spaces, or incorrect model names. This can lead to API errors and a poor user experience.